This application claims the benefit of Korean Application No. 98-18661, filed May 23, 1998, in the Korean Patent Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a home network, and more particularly, to a method for connecting to server devices through a browser in a browser-based home network, and apparatus therefor.
2. Description of the Related Art
Recently, various digital devices such as a digital television DTV, a digital video cassette recorder DVCR, a DVD player DVDP, and a digital set-top box have appeared.
The IEEE 1394 approved by the IEEE committee is highlighted as the interface for such digital devices. FIG. 1 shows a protocol stack that general IEEE 1394 devices have. A physical layer 100 which is the lowest layer receives a bit stream from a link layer 110 which is an upper layer during transmission and acquires the right to use a serial bus. The physical layer 100 encodes the bit stream, converts the encoded bit stream into an electrical signal, and transmits data to the bus. During reception, the process is reversed. The link layer 110 manages data in units of a packet, integrates and disintegrates a packet, detects errors, and manages a bus cycle. A transaction layer 120 provides a transaction such as read, write, and lock and performs asynchronous communications with other nodes on a 1394 bus using services provided by lower layers.
The link layer 110 has cycle control, packet transmission and packet reception protocols which perform cycle control, packet transmission and packet reception, respectively. The physical layer 100 has encode/decode, arbitration and media interface protocols which perform encoding/decoding, arbitration and media interfacing, respectively. These protocols are specified in the IEEE 1394 standard.
When devices are connected using the IEEE 1394, it is not enough to perform data transmission between devices with only an IEEE 1394 specification. Namely, rules with respect to processes of securing a connection between devices for transmitting and receiving A/V data and an isochronous channel for transmitting the A/V data should be established between devices. For this, an IEC 61883 specification exists.
As noted, the IEC 61883 specification is a standard for specifying connection management of a system connected by a digital interface according to, for example, the IEE 1394 specification. An input plug control register (IPCR) and an output plug control register (OPCR) are specified by the IEC 61833 specification and perform connection management between digital devices.
In the IEC 61883 specification, a function control protocol (FCP) a connection management protocol (CMP) 130 are defined. The CMP defines the structure of software for managing the isochronous connection between devices. The FCP provides a framework for transmitting commands such as an A/V control command and transaction set AV/C CTS. Another characteristic of the IEC 61883 is to define a common isochronous packet CIP header structure. The CIP header has information on a source stream included in the isochronous packet.
A control command is used in order to control the devices in a conventional specification meeting the specification of the IEEE 1394 and the specification of the IEC 61883. The AV/C CTS is a representative control command. Every function of devices is defined by a code of a hexadecimal number system. For example, a play command of the VCR is defined as xe2x80x9c0xC8xe2x80x9d.
In a digitized home device environment, one device may be used as a control center for controlling other devices. However, the following problems occur. Here, the device for controlling other devices is called a controller and the devices to be controlled are called target devices. First, the controller should include all the command sets with respect to the respective target devices, which is a considerable burden on the controller with respect to software and hardware. Second, since the target devices do not know commands other than the commands included when products are brought to market, they cannot be controlled by new client devices. Therefore, it is not possible to easily conform to a digitized home device market which rapidly changes. Third, it is not easy to provide a graphical user interface. It is difficult to define a unified type of GUI which can be applied to all kinds of devices. Also, defining the type of GUI with respect to each group of products has its limitations. Such problems are due to inconsistency of architecture. The problems can be easily solved by selecting a client/server method as in the widely applied TCP/IP architecture.
FIG. 2 shows a protocol stack to which the present invention is applied. Each device operates like a web server on the Internet. At this time, the IEEE 1394 is used as a network interface. A TCP/IP layer is put on the IEEE 1394. Every device operates according to the HTTP protocol. A device which has a display device such as a DTV or a PC includes a web server and operates as a web client. A user accesses the respective home pages from web server devices using a web browser built into the client device, thus controlling corresponding devices.
The MPEG stream box denotes an audio/video data stream compressed by an MPEG algorithm, for example, MPEG-2. The box labelled IEC 61883 is specified in the IEC 61883 specification as a CIP (Common Isochronous Packet) header structure. The CIP header contains information of the source stream included in isochronous packets. Thus, the IEC 61883 denotes a part of the IEC specification when the CIP header structure is specified.
In a protocol stack environment having the structure shown in FIG. 2, a server device which has a web browser accesses a web server device by the browser thereof and controls the server device which operates as the web server. For this, connection to the server device should be made by the web browser. The method for contacting the server devices through a web browser should be convenient to the user. The server devices desired by the user should be distinguished from the server devices which are not desired by the user during the connection. The connection should be performed considering compatibility among the server devices with respect to data formats.
It is an object of the present invention to provide a method of connecting to server devices by a browser of a browser-based home network, by which a user can easily and rapidly connect with server devices.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Accordingly, to achieve the above and other objects of the present invention, there is provided a method for connecting to server devices in a browser-based home network comprised of server devices including a function of a web server and a client device into which a web browser is installed for controlling the server devices through the web browser, comprising the steps of preparing a home page of the client device so as to display server device icons for selecting the server devices to be connected to, selecting one of the server devices to be connected to in the home page, reading a register OPCR in which an operation state and channel information of the selected server device are recorded from the server device, and completing connecting to the selected server device by recording the channel information of the selected server device in a register IPCR when a read operation state is active and checking the operation state of the server device by reading the register OPCR at predetermined time intervals when the read operation state is inactive.
It is preferable that the step of preparing the home page of the client device includes generating an identification information storing unit of the server devices to be connected to, and the method further includes checking whether the selected server device is registered in the identification information storing unit, wherein the step of reading a register OPCR includes reading the register OPCR only when the selected server device is registered in the identification information storing unit and not connecting to the server device when the selected server device is not registered in the identification information storing unit.